Concrete tunnel lining



C. T. FORSBERG CONCRETE TUNNELLINING Filed May 18, 1936 5 Sheets-Sheet 1 IN V EN TOR.

4 TTORNEYZ 1 Oct. 26, 1937. c, T, FORSBERG 2,096,850

CONCRETE TUNNEL 'LI NING Filed May 18, 1936 5 Sheets-Sheet 2' JZaZ w/ INVE OR.

ATTORNEY.

Oct. 26, 1937. c. 'r. FORSBERG CONCRETE TUNNEL LINING s sheets-sheet s Filed May 18, 19.36

' ATTORNEY' m M Y B Patented Oct. 26, 1937 UNITED STATES ATENT OFFICE]..-

CONCRETE TUNNEL LININGY Carl T. Forsberg, New York, N. Y. Application May 18, 1936, Serial No. 80,242

' 13 Claims.

This invention relates to improvements in tunnel linings and more particularly to means for and method of placing concrete linings within the metallic hollow cylindrical casing of subaqueous and other tunnels.

It is an object of the present invention to prevent the formation of hollow spaces within the concrete linings of tunnels.

It is another object of the invention to provide means for completely filling each segment of the metallic tunnel lining completely with concrete during the process of placing the same.

It is a further object of the invention to eliminate the necessity of drilling through-the. hardened concrete lining into empty spaces of the concrete lining and to fill them by pressing grout into them.

'It is a further object to provide a strongeran more uniform concrete lining in a single operation than has heretofore been possible by the refilling method.

It is another object to reduce the labor required for forming concrete-linings and thereby to accelerate the time required for building a tunnel.

It isa further object to make it possible to produce a stronger concrete lining by producing monolithic concrete (concrete in one piece) rather than concrete in more than one piece by the refilling method.

With these and other objects in View the invention consists in a novel method of procedure in preparing the metallic outer tunnel lining for placing of the interior concrete lining and in novel means and arrangements tobe applied for this purpose which will become clearer as the description progresses in connection with the appended drawings in which Fig. l is a vertical section through a tunnel provided with an exterior metallic lining embodying the present invention.

Fig. 2 shows a quadrant vertical section transverse of a metallic tunnel lining embodying the present invention.

Fig. 3 is a longitudinal section of the tunnel linings on line 3-3 of Fig. 2.

Fig. 4 is an interior view longitudinally of the tunnel on line 44 of Fig. 1 showing only the metallic lining.

Fig. 5 is a vertical transverse quadrant section through the metallic lining of a tunnel as shown in Fig. 2 prepared for placing concrete in accordance with the present invention.

Fig. 6 is an enlarged detail'section showing a joint of two cast metal sections of a tunnel lining embodying the present improvements and prepared for placing the inner concrete lining in accordance with the improved method.

Fig. 7 shows a section similar to that of Fig. 6 through a sheet steel tunnel lining also prepared for placing the interior concrete lining in accord ance with the improved method.

Fig. 8 shows a modified form of the invention for use on a cast metal tunnel lining.

Fig. 9 is a sectional view on line 99 of Fig. 8.

Fig. 10 is a detail of a cross arm for holding the air tubes on the segment flanges.

Fig. 11 is a detail of a-tubular rivet for joining the tunnel segments.

In the construction of subaqueous'and other tunnels cast iron or steelrings consisting of segments I5which are boltedv together by means of flanges t6 and ii thereon are generally used to form a. cylindrical lining within the blasted or otherwise excavated tubes- Thesegments form: ing Qne ring are preferably oifset. or'staggered against those of the two adjacent. rings. so that the horizontal flanges ll form broken lines-.101 gitudinally of the tunnel.

When a plurality of liningrings sembled and bolted'together circumferentially by bolts 19 and longitudinally bybolts l9a, the hollowportions of all segments it are filled with concrete to a'point beyond the flanges Land I! so as to form a solid concrete cylinder l4 of several inches thickness inside of said flanges. For this purpose a form preferably of sheet metal plates curved to fit the inner radius of the, con

have been ascrete lining to be formed is supported by false- 7 work and spaced the desired distancefrom. the inner faces or edges .ofiflanges l6. and, I1 within the rings to be concreted.

At first a form-segment is placed above the bottom segments of the rings as viewed in Fig. 5, and the spaces between this form and the metal webs of the segments l5 are filled with plastic concrete. When this concrete has set the forms are moved circularly upward opposite the tunnel rings to cover with the same spacing the next higher segments and concrete is again poured between the forms and webs of the tunnel segments and this, process is continued until all segments of the metallic tunnel lining are covered by a hollow concrete cylinder of approximately uniform thickness of several inches inside of flanges I6 and ll. 7

While this method is satisfactory for the lower half of the tunnel lining it is not so for the upper half of the lining, as in pouring the concrete the fiangesll prevent the complete filling of the segments above the central horizontal plane of the tunnel and at the places indicated at' l8 air is trapped in each segment forming hollow spaces in the segments l5 which spaces increase in size towards the top of the lining as shown in Fig. 2.

Of course by pushing and tamping, these spaces can be partly filled with concrete but not one tirely. It has therefore become, the practice to drill a. pair of holes into these hollow spaces when the concrete has set and press cement grout into tallic tunnel lining' are filled consecutively m longitudinal direction of the tunnel the tubular 1 members 22 can be attachedto the bolts in the them through one hole, while the air escapes from which a central stem 2Ia extends.

through the second hole, obviously a tedious and costly process. It is an object of this invention to prevent the forming of these air pockets bya simpler and less expensive method. 7

. The present invention contemplates providing novel mechanical means for preventing the for.- mation of air pockets at the joints when pouring concrete.

' and stem 2 l a is bent around the abutting flanges of the two segments 15 joined together bysaid bolt. The cross arms 2lb are, bent around a tubular member 22 which is curved around the same flanges extending from the highest point in the lower segment l 5 to approximately the middle .of the next higher segment I5. The cross arms 21b hold'the member 22 securely connected a 'to flanges l1. Each cross'arm' 2lb is preferably provided with an aperture 2lcthrough which a tie wire 25 may'bepassed whennecessary to tie where. air is trappedas shown in Fig. 2. When up the long arm of tube 22 and hold it in desired position; e j 3 I Itiwill be seen bycomparingFigs. 2 and 5 that the lower openings, of tubes 22 are located in the segments at the highestppoints of the spaces l8 concrete is'poured intothese segments the other-;

wise trapped n: escapesthrough tube 22 into the,

next higher segment and exhausts ata place higher than the top of 'the concrete in the lower 7 opening be plastered ,7 over.

segment; The pouring'of concrete may proceed 'uninterruptedly because from each higher se gment the air escapes in the same'manner, so that the plastic .concrete will completely fill them when pressedin except .the highest segment in i which two tubes 22 will Jdischarge air from the next two lower segments. A third straight vertical tube 23 .is mounted in the top segment to reach to the highest point in that segment. Tube 23 ispreferably passed through an aperture of form 20, and preferably consists ofgtwo parts joined by a union 23a. sothat thelowerpart may be removed when the concrete has set and the The tubes 23 are preferably provided at their upper ends with :a ,wire hook; 23b. welded to the outside of-the tube. This hook is placed into an aperture formed in the wall of tubes 22 near theirupper or' lower end to prevent vertical motion asillustrated. in

Figx5. 'Hook 23b permits thelower end of. tube 1 23 to move when the aperture in the form is out of verticalalignment with the top of the tube which must remain in fixed place. It is evident that by means of tube 23 the uppermost segments of the. tunnel rings are alsor'eliev ed of all air that H could be trapped therein and .that they, like all other 'seg'ments, will be completely andsolidly filled with concrete. When the rings of the mecircular flanges 16 of the metallic lining and bent Fig. shows the metallic segmentsin the upl r Each bolt I9 carries a sheet metal the highest space in each segment to be filled into the adjacent forward tunnel segment which will be filled later as shown in Fig. 3 with the same beneficial result. The tubes-23 alone may be used to remove the trapped air from the high spaces of any segment by mounting them radially by means of cross arms 2| or other suitable means iso 'that their upper end reaches into the hi space where air will be trapped and their lower end extends through the form plate as shown 'in Fig. 5.

v In Fig. 8 a modified tubular means for removing trapped air. from the segments I5 is illus trated. Itshows that one of the bolts I9 is omitted and in its place a tubular rivet 24 is used.

It will be seen from Figsl 5 and 6 that the bolts I9 do not quite fill their apertures but leave a hollow annular space between bolt. and flange metal.

closely and thethickness of its wall can easily be The tubular rivet 24 fits the aperture" so' proportioned that itscross-sectional area is equal to that of the bolt a t-the root of its thread and therefore equals the tensile and shearing strength vof'the solid'bolt. When the'tubular 7 rivet has been placed into its aperture the cylindrical end is upset into the countersunk opening. of the bolt hole and the flanges I! or I6 areas securely riveted together as they can be bolted;

A short tube 25 provided'with a curved end portion is then tightly driven into' the hollow ofthe tubular rivet 24 so that the opening'of the curved" portion comes into the highest part of the lower segment where air may betrapped. A straight from the side of the highe'r segmentj l5 into the hollow part of the rivet or tube 25 to complete an ,tube 26 of smaller diameter is 'thentightly driven air passage from the top space of a lower tunnel 7 segment into the 'free air spaceof the nexthigh'er one. K 1 1 In practice more thanone; or allbo'lts joining two segments may be replaced by these tubular rivets without impairing the strength of the joints and the circuitous pathfaround the segment flanges maybe eliminated in a 'neat and inex pensive way.

The air tubes22, 25 an 26 remain in the'solid V concrete and serve as reinforcing rods of the joints between the segments in circular and lon-" gitudinal directions. 'I'hose parts of tubes 25 and r 26 which are within the'tubular rivets 24 are preferably slightly tapered to provide a stronger joint and the openings in the free ends'of tubes By the above described method and possible to build a monolithic tunnel lining in one continuous operation and to eliminate the work of drilling into air spaces and of filling them with grout. In addition thereto the lining produced by this process and the means described furnishes a stronger lining by means of the additional tubular steel reinforcing which joins the segments means it is to each other in addition to the' bolts which hold V the segments together.

' It willbe understood that modifications may be 7 made in the details of" execution of the aforedescribed process withoutfldeparting from the pri'n;

ciple or the invention and it is desired to be lim-' i 'ited only by the prior art and the appended claims. I

I claim:

1. The herein described method of constructing tunnel linings which consists in permanently placing an arcuate shaped form having inwardly extending peripheral flanges in the excavated tunnel, mounting another form of similar shape on the first named form so that their flanges abut, bolting the flanges, placing a tubular member with one opened end in the lower form adjacent its flange and with its other opened end in the upper form at a point remote from its flange, mounting a temporary arcuate shaped form adjacent the inner edges of the flanges, pouring plastic concrete into said forms and permitting said concrete to harden and lastly removing said temporary form.

2. The method of preventing the formation of air bubbles in a concrete tubular tunnel lining consisting in placing a tubular member between the sectional joints of the forming member, with one end of the tubular member in one section adjacent the joint and with the other end of the tubular member in the other section remote from the joint.

3. In a tunnel lining having arcuate shaped segments and inwardly extending and abutting flanges, a tubular member having one of its open ends bent around the flanges and terminating adjacent the innermost end of the flange in one segment and having its other end terminating in the adjacent segment at a point remote from its flange for exhausting air from the first named segment.

4. A segment of a tunnel lining comprising an.

arcuate section of metal lining having inwardly extending and abutting flanges, means for securing the flanges together, a bracket depending from said fastening means and a tubular member supported by said bracket, said tubular member having one of its open ends positioned on one side of the abutting flanges and its other open end on the other side of the flanges, for exhausting air from the first named side of the flanges.

5. A tunnel lining comprising a plurality of arcuate shaped sections having abutting flanges, means for fastening the flanges together, the sections above the horizontal plane of the tunnel being provided with means for exhausting the air therefrom, said means consisting of a tubular member supported by each pair of abutting flanges, with one of its open ends in one section adjacent the innermost end of the flange of said section and with its other open end in the other section remote from its flange.

6. A tunnel lining comprising a plurality of arcuate shaped sections having abutting flanges, a bolt passing through said flanges for fastening the same, a bracket fastened to the bolt, integral arms on said bracket, and a tubular member supported by said arms, said tubular member having one open end bent around the abutting flanges and terminating at a point adjacent the inner end of the flange of one section and its other open end positioned in the adjacent section remote from its flange.

7. Tunnel lining construction comprising a plurality of superimposed arcuate shaped segments with inwardly extending abutting flanges, bolts passing through the abutting flanges for fastening the same and a device positioned between the joints of the respective abutting segments above the horizontal axial plane of the tunnel for exhausting the air therefrom when concrete is poured therein, said device consisting of a tubular member having one of its open ends positioned in one segment adjacent its abutting flange and having its other open end positioned in the other adjacent segment at a point remote from its abutting flange, and means for supporting said tubular member in position, said means consisting of a plate member connected to the fastening bolt and arms on the plate for holding the tubular member.

8. In a tunnel lining having arcuate shaped segments and inwardly extending and abutting flanges, a device for exhausting the air from the lining segments above the horizontal axial plane of the tunnel, said device consisting of a tubular rivet passing through the abutting flanges, a curved tubular member extending into said rivet and into one segment, and a second tubular member extending into said rivet and into the other adjacent segment and a screen carried on the outer end of the curved member.

9. In a tunnel lining having arcuate shaped segments and inwardly extending and abutting flanges, a device for exhausting the air from the lining segments above the horizontal axial plane of the, tunnel, said device consisting of a tubular rivet passing through the abutting flanges, a curved tubular member extending into said rivet and into one segment and a second tubular member extending into said rivet and into the other adjacent segment.

10. In a tunnel lining having arcuate shaped segments and inwardly extending and abutting flanges, a tubular member having one of its open ends bent around the flanges and terminating adjacent the innermost end of the flange in one segment and having its other end terminating in the adjacent segment at a point remote from its flange for exhausting air from the first named segment and another tubular member hinged to the remote end of the first tubular member and having one of its open ends terminating exteriorly of the segment for exhausting air from said segment.

11. In a tunnel lining having arcuate shaped segments, a device for exhausting air from the individual segments comprising a tubular meme ber having one end positioned in the segment and its other end positioned exteriorly of the segment.

12. The method of preventing formation of air pockets-in concrete tunnel linings Within segmental steel linings of a tunnel which method consists in providing an air passage by fastening a tubular member to one of the steel segments so that its inlet opening is near the top of said segment and its outlet opening outside of the limits of said segment and then filling said segment with plastic concrete.

13. The method of preventing formation of air pockets in concrete tubular segmental tunnel linings consisting in placing a tubular member between the sectional joints of the forming member in one section adjacent the joint and with the other end of the tubular member at a higher plane in the other adjacent section remote from the joint and by placing another tubular member in the uppermost segment so that one of its ends is in communication with the remote end of thejoint tube and its other end extends exteriorly of the forming member to the atmosphere.

CARL T. FORSBERG. 

